diff --git a/racket/src/racket/src/number.c b/racket/src/racket/src/number.c
index 0897c14555..ca62214756 100644
--- a/racket/src/racket/src/number.c
+++ b/racket/src/racket/src/number.c
@@ -260,14 +260,14 @@ READ_ONLY Scheme_Object *scheme_zerol, *scheme_nzerol, *scheme_long_pi,
    Make x87 computations double-precision instead of 
    extended-precision, so that if/when the JIT generates
    x87 instructions, it's consistent with everything else. */
-static void to_double_prec(void)
+XFORM_NONGCING static void to_double_prec(void)
 {
   int _dblprec = 0x27F;
   asm ("fldcw %0" : : "m" (_dblprec));
 }
 #endif
 #if defined(ASM_DBLPREC_CONTROL_87) || defined(ASM_EXTPREC_CONTROL_87)
-static void to_extended_prec(void)
+XFORM_NONGCING static void to_extended_prec(void)
 {
   int _extprec = 0x37F;
   asm ("fldcw %0" : : "m" (_extprec));